Floor grinding machine



FIG. 1 is a perspective view of a floor grinding machine incorporating my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side view thereof:

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines shown in the drawings illustrate portions of the floor grinding machine that form no part of the claimed invention. 

CLAIM The ornamental design for a floor grinding machine, as shown and described. 